1. Field of the Invention
The present invention is concerned with hydrocarbon desulfurization, denitrogenation and aromatics saturation and a catalyst therefor. More particularly, the invention is concerned with a metal, metal oxide and/or sulfide supported on a base of titania-zirconia or of titania-zirconia-alumina.
2. Discussion of the Prior Art
It is well known that many petroleum stocks contain sulfur and nitrogen. It is desirable for many applications of the petroleum stock itself or of the products made from it that these be removed. This is an operation requiring a catalyst, and one in common use is an alumina base containing cobaltia and molybdena.
So far as is known, no art discloses catalysts or catalyst supports made exclusively from titania-zirconia or titania-zirconia-alumina, or the use of such supports containing cobaltia and molybdena or other metal oxides or sulfides in hydrotreating reactions. U.S. Pat. No. 3,159,588 does disclose a catalyst containing various combinations of titania and zirconia, but it is essential to the composition that silica be present therein. There is no disclosure in U.S. Pat. No. 3,159,588 of the presence of molybdena or cobaltia. U.S. Pat. Nos. 2,597,880, 3,137,658 and 3,887,494 teach compositions of silica-titania, some containing other metals, in hydrocarbon conversion reactions. U.S. Pat. No. 3,264,227 teaches the manufacture of a silica-zirconia-alumina catalyst useful in hydrocarbon conversion reactions.
U.S. Pat. No. 3,278,421 is concerned with refractory inorganic oxides comprising alumina, titania and zirconia, among others, which may contain certain metallic components. There is, however, no disclosure of the particular catalysts of the present invention.
U.S. Pat. No. 3,546,103 teaches hydrodesulfurization with a catalyst of cobalt and molybdenum on an alumina base.
Some of the above-mentioned compositions of the prior art, as for example the silica-titania-zirconia composition, allegedly have desulfurization capabilities. However, the prior art mentioned does not teach or suggest the catalyst of this invention or its use in hydrotreating feed stocks.